


Copper Compounds, When Ignited

by SailorCresselia



Category: Kamen Rider Zero-One
Genre: Emotional Hurt/Comfort, Gen, attempts at bonding over shared trauma, the level of success at said bonding is variable
Language: English
Status: Completed
Published: 2019-12-10
Updated: 2019-12-10
Packaged: 2021-02-25 22:47:02
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,589
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21743206
Author URL: https://archiveofourown.org/users/SailorCresselia/pseuds/SailorCresselia
Summary: Isamu isnotfollowing Hiden because he’sconcernedabout him, and the little voice in his head saying otherwise can shut up, thank you very much. But he has to admit, seeing the Hiden Intelligence CEO start shaking like a leaf in the middle of a restaurant is slightly concerning.
Comments: 4
Kudos: 58





	Copper Compounds, When Ignited

**Author's Note:**

> I originally wrote this after episode 6 aired, and thus only make hints of developments that occurred after that point. 
> 
> Title comes from a method of changing the colors of flames: fireworks use a copper compound to create blue effects.

Isamu has to bite back a groan when he sees Hiden and his HumaGear walk into the restaurant. It’s his day off, damnit, and he’d really hoped that he wouldn’t have to deal with any Magia today. But experience has long since taught him that about 2 out of 3 times that they run into each other, a battle’s bound to follow.

Damnit.

Hiden nods in his direction, and Isamu reluctantly nods back. They aren’t friends, or allies, or anything of the sort, but they’re in public, and he’s not a total ass.

He doesn’t mean to overhear anything. He’s just waiting for his food, really, and they were seated next to him.

“Seriously, Izu, you _can_ sit down, I don’t mind!”

The HumaGear assistant tilts her head at Hiden, in that way she keeps on doing. “President Aruto, being seated is not a requirement that I have. I am intended to be ready to accommodate your requests at any moment.”

Hiden laughs a little. “Well, right now, my request is for you to sit down. It makes my legs hurt for you just watching you stand all the time.”

She blinks, seemingly processing this. “I do not understand. How can a human feel pain because someone else is upright?”

With a small groan, Hiden leans forward. Isamu kind of wonders what face he’s making – the CEO is facing away from him. “It’s not a… literal pain, really. It’s a sympathetic sort of thing; when you see someone doing something that you would find uncomfortable, sometimes it can make you feel like you’re feeling what you would feel if you were the one doing it. Does that make sense?”

She simply blinks at him again, before acquiescing. Huh.

The guy _does_ have a way with words. It’s always weird seeing him treat HumaGears like they’re human, but he _is_ running a company revolving around them. Isamu resolves himself, once again, to the fact that he will never actually understand Hiden.

A little while later, Isamu has received his food, Hiden has ordered, and the assistant has gotten weird looks from about half of the people here, which Hiden has summarily ignored. It’s none of his business, why is he paying so much attention?! He’s just bored, and it’s a habit from work. That’s all. Nothing about wondering if he’s going to crack a joke, or when the next threat will show up, or wanting to understand the guy.

The waitstaff start up a song, carrying a cake over to a family a few tables away. It’s some kids birthday, looks like, and when the candles are lit at the table, turns out his family sprung for some fancy novelty colored candles, those things that have all the different colored flames. Cute.

As the song intends, most of the restaurant looks up to see what the fuss is… and since Hiden is right in between Isamu and the little party, it’s clear that he looked up from his phone to see, too.

But when the candles were lit, Hidens phone dropped to the floor, and he stopped moving.

That’s unusual. Even when he’s being interrogated, the guy is always moving at least a little. But he’s frozen – except for how his shoulders are shaking.

“President Aruto?” The HumaGear tries to get his attention. “Is something the matter?”

It’s not until the kid blows out the candles that Hiden responds in a nearly inaudible whisper. “Izu. I have to go. Do you mind paying for me, and getting the meal boxed up and getting it into the office fridge for me?”

A blink, and then she nods. “As you request, President Aruto.”

“Thank you.” Shakily, he picks up his phone, and quickly leaves.

…Isamu waves down a server – an increasingly rare human one, at that. “Can I get my bill?”

* * *

He’s not worried, not at all. But it’s weird. Hiden _never_ goes anywhere without that HumaGear, and he’d specifically told her to go to the office. Implying that he’s not going back there, himself.

Isamu is _not_ following him because he’s _concerned_ , and the little voice in his head saying otherwise can shut up, thank you very much. He was already done, and happened to be going in the same direction. That’s all.

Except that Hiden is going into a residential area, on foot, and decidedly _away_ from where Isamu knows any Hiden Intelligence offices are.

…Actually, Isamu lives a few blocks from here, himself. …Wait, is this where _Hiden_ lives?! He’d expected that the CEO would live, you know, somewhere fancy. Because he’s a CEO.

The name label of the apartment, that Isamu very definitely does not check, reads ‘Hiden, A’.

…huh. Well, nothing to it, then. Isamu waits a little while, to see if he comes out on his own. But when fifteen minutes go by, with no sign of life – or of the lights going on – knocks at the door.

“Hiden? You in there?”

No response.

“Hiden? I… saw you at the restaurant. Is everything alright?”

There’s a moment of silence, and Isamu is about to call out again – or maybe shoot out the lock – when Hiden replies. “The door’s open. Just come in, Fuwa.”

…Oh. Well, it would have saved some time if Hiden had just said that to start with. At least he spared himself a lock. Cautiously, just in case this is some sort of trick, Isamu opens the door.

The small apartment is kind of a mess. There’s no dust, so it looks like he’s still been living here this whole time, since taking over his company. It just looks like a normal bachelor pad.

He’s not sure what he’d expected from a CEO that was living in the suburbs this way. Definitely something tidier, at least. But it… just looks like a normal bachelor pad. Things are tossed wherever – except for the floor. The floor is _spotless_ , for reasons that Isamu just can’t fathom. Why keep just the floor clear- wait, that’s not the point of why he’s here.

All told, Hiden’s apartment isn’t what Isamu would have expected from the CEO of a company. In fact, the only sign that the resident is anyone but an average person is the suit jacket tossed haphazardly on a side table. He has to fight the urge to pick it up and fold it.

As for Hiden, he’s in one of the hoodies he always has under that jacket – and Isamu’s never understood _that_ , either, but it’s not his place to criticize his clothing, just his business. But he’s laying on his stomach, on a battered couch, scrolling through something on his phone.

“Hiden?”

“Which year were you in?”

“…I’m sorry, what?”

Hiden doesn’t look up as he talks, just keeps scrolling. “In Daybreak Town. Which year of school?”

“…First year of high school. What does it matter?”

“Gives me a way to map out what happened. You said the rogue HumaGear were climbing up the walls… What floor were you on, the second? I remember that school being three stories…”

_‘He remembers the school…?’_ “Yeah, I was on the second floor. What does it matter?”

“Helps me pinpoint some stuff. Thanks. So, you’re a couple years older than me, then, and must’ve been in some club or other, since you were _at_ school when everything happened.” Hiden shrugs. “It’s weird. You were a lot further out from the epicenter, but if the HumaGears were rampaging both before and after the first explosion… I have to wonder what actually stopped them…”

Isamu narrows his eyes. “Did you have some sort of revelation about that day while at a _restaurant_?”

“Heh, I wish.” He makes a few quick selections, and when he points his phone at the wall, the image he was looking at is projected up onto it. It’s two maps of Daybreak Town – one before the catastrophe, and one now. “The factory we visited with Gou and Anne was this one…” He makes a gesture on the phone, and a small icon of a bus appears over the factory on both maps. “Your school was _here_ -” Another gesture, and an image of the mask from Shooting Wolf appears. “-and this is the area where the first explosion was.” He highlights a round area, in a brighter blue than Isamu’s own. Hiden pauses. “That's quite a distance… and then, right over here… This was a little bit inside of the outer edge of the first explosion.” He hesitates, and the next icon that appears – much closer to the explosion than Isamu had been – is of Rising Hopper. “That was where I was.”

…Wait. “Hold on. You were there?!”

Hiden nods. “I don’t remember it all too well, since I was ten and all. But that first blast… the flames were bright blue, even after the explosion. The rubble burned bright blue.” He sighs. “I don’t remember much further after that. I think I kinda shut down for a while, myself.” Slowly, he sets the phone down, the hologram winking out as he does so. “I was ten, and just… was playing around with – I just wanted to make him laugh _for real_ , y’know?”

“…Oh.” Unbidden, a memory of one of the many arguments he and Hiden have had over the past few months comes to mind.

_‘After my father died, I had a HumaGear to help me through it, so. Please, he’s already said he’ll turn himself in, but please just let her do this audition.’_

“The HumaGear who took over for your father, then.”

Hiden nods. “The HumaGear who looked _exactly_ like my father. I don’t think it really clicked with me that he _was_ a HumaGear, actually. I was a little kid, and he looked the same. And the technology to make HumaGear look like… well, to make them look human wasn’t nearly as refined as it is now, as far as anyone knew.” He barks out a short laugh. “Only the best for the grandson of their inventor, I guess. Not that it helped in the long run.” He goes quiet again.

Unfortunately, seeing as Hiden is mentioning the explosions, and with his apparent proximity to such, Isamu can see where this story is going. “It was destroyed, wasn’t it.”

Hiden can only quietly nod. “He was shielding me from the blast. I was pretty out of it afterward, but he… he was killed protecting me.”

_Yikes_. “Hiden-”

“ _Aruto_.” He smirks. “If you’re going to follow me home and check in on me, I think we can use our names at that point. And would you sit down, already? At least Izu has a justification.” The smile fades a little. “I do appreciate it, though. Did anyone else there notice me freaking out?”

Isamu shakes his head as he sits down on the couch next to Hid- Aruto. “Aside from your HumaGear, no, not that I noticed.”

“Good. …Good.” He lets himself fall forward into the couch. “Thanks, Fuwa.”

“Isamu.” He smirks. “Like you said, might as well use our names at this point.”

“Hah! Isamu, then. Thank you. For noticing, and for showing up to check on me. I appreciate it.”

“Well, seeing as we wind up in firefights together so often, I figured it would be reasonable to ensure that you were alright.”

Aruto grins. “Awww, you _do_ care!”

“Sh-Shut up! Why are you even living here, anyway? I’d think that you could afford somewhere better.”

Aruto doesn’t answer for a bit. “…If I moved somewhere more ‘suitable’ for a CEO, it’d be like lying about who I am. I didn’t get this job because I wanted it, or because I earned it, or anything. It’s definitely nepotism of some sort, don’t get me wrong, but it was _definitely_ not my choice. One of many questions that my grandfather left behind is why he insisted, via his will, that _I_ take over the company. We hadn’t spoken in years, so… it doesn’t make sense.”

“And yet, here you are.”

“And yet, here I am, after turning it down. Being Zero One-” He waves his driver in the air “-was part and parcel with taking the job. I forgot about that little detail when I had Izu hand me the belt at the dreampark.”

Isamu scoffs. “So you _were_ there, after all, you stupid grasshopper.”

“Hey, I _had_ gone to try and get my job back!” Aruto laughs, before calming. “But I couldn’t let Taro – that was the HumaGear’s name, before he was turned into a Magia – I couldn’t let him hurt anyone else. He had to be stopped… so I had Izu hand over the belt. She… came with the job, too. I’ve never let her come back here with me. Don’t want to cross my two worlds.” He shrugs. “After that, you basically know the rest. I put the belt on, got my mind uploaded to the satellite for the tutorial on how to use said belt, woke back up, transformed, and fought the battle.” He shrugs. “I suppose you and Miss Yaiba were dealing with the trilobites, right?”

“We were.” Isamu nods, before doing a double take. “Wait, what was that about having your mind uploaded?!”

Aruto props himself up. “Did… that not happen for you?”

“NO!”

They stare at each other for a minute before Aruto scrunches his face in a frown. “Okay, I’ve got a proposal. We learn to summon ghosts, summon my grandfather, and interrogate the heck out of him about whatever it is that’s going on.” He pauses. “At this point, I wouldn’t be entirely opposed to punching him to get the info, either.”

“Are you serious about that?”

“Not really, but you have to admit, it’s kind of tempting, right?”

A whirring noise interrupts the conversation, and a small floor-cleaning bot rolls into the room. …Hold on. “Is… that a foam knife taped to that thing?”

Aruto beams. “Ye. Cute, huh?” He leans down and pets the bot on top of its chassis, to which the bot chirps, and turns away to resume cleaning the rest of the room. “Toge-chan’s the only robot I’ve had of my own, up until the whole CEO thing.”

Isamu pulls his legs up.

“Seriously?”

“I am being cautious.”

“He’s a _roomba_.”

“There is every chance that that robot has something pointy under that foam knife. Even I’ve seen the jokes.”

Aruto chuckles in disbelief. “You _really_ think I would _actually_ arm my _roomba_.” Isamu just glares at him. “…Okay, fair. But also I prefer _not_ getting jabbed in the ankle, and don’t want my furniture to get all damaged. ‘Sides, Toge-chan’s a good roomba.” He leans forward, calling toward where the cleaning bot is puttering across the room. “Isn’t that right?”

The roomba chirps.

“…I’m starting to worry about you, and it’s _not_ because of the apparently shared PTSD this time.”

That comment earns Isamu a half-glare. “Floor-cleaning droids like Toge-chan have incredibly basic AI, I’m not treating him any different than I would a cat or dog. Some of us need interaction in order to keep going, and he’s what I’ve had at home.” There’s a pause. “…What about you?”

“Eh?!”

“Isamu, your coping method kind of seems to have gone straight to ‘guns’, and that’s… probably a bad thing.”

“Pfeh.” He gets up from the couch. “It’s served me well enough this far. See you around, prez.”

As he leaves, Isamu staunchly ignores the concerned look that Aru- that Hiden is giving him. He’s dealt well enough for the past twelve years. He’s perfectly fine.

**Author's Note:**

> The [original version of this story](https://sailor-cresselia.tumblr.com/post/188316746151) was posted to my tumblr, sailor-cresselia, in early October 2019. This version has been updated and refined.
> 
> And yes, Aruto has his own incarnation of Stabby the Roomba. Or, well, 'Pokey', as he'd probably be localized.


End file.
